Impact Of A Novel Surgical Instrument On Topography Guided Lasik Outcomes

To study the visual outcomes of topography guided LASIK using a novel surgical instrument: Khatib's LASIK flap protector and globe stabilizer. This instrument is applied on the eye during LASIK ablation. The head of the instrument covers the flap hinge and retracted flap undersurface to avoid accidental flap ablation, while the instument body helps to stabilize the globe so as to prevent movement during ablation.

This was a single-centre triple-blinded prospective randomized trial of Topo-guided LASIK outcomes using 2 different methods. 60 eyes of 30 patients were recruited, where 1 eye of each patient underwent treatment using conventional surgical techniqies (control group), while for the 2nd eye, the Khatib's LASIK flap protector and globe stabilizer was used (study group). The eye that was assigned for a particular group was selected by simple randomization. Surgery was performed by a single surgeon using Femtosecond laser flap and Contoura LASIK. Post-op assessment included comparing visual acuities and higher order aberrations (HOAs) between the groups. Subgroup analysis was seperately done for cooperative and uncooperative patients. 

Post-op assessment of outcomes was performed at 3 months following surgery. Although there were no significant differences in the uncorrected visual acuity between the 2 groups, the induced Higher order Aberrations (HOAs) showed significnt differences. Total HOAs (RMS) induced by surgery were significantly lower in the study group (mean 0.11) vs control group (mean 0.2) (p 0.005). Spherical aberration change was not significant, but both vertical coma (p 0.002) and hortizontal coma (p 0.02) change were significantly lower in the study group compared to controls. These effects were more pronounced in uncooperative patients compared to patients with good cooperation during surgery.

Using a globe fixation instrument during LASIK ablation improves visual outcomes of surgery, more so in uncooperative patients with poor fixation.